In recent years, as environmental measures against global warming, LEDs have rapidly been used as light sources of general lighting apparatuses and as light sources of backlights provided in TVs. Such a light source is configured by an LED lighting module (light-emitting device) that is configured to emit white light. Examples of a method for generating white light with the use of an LED encompass (i) a method in which white light is generated by combining the three primary colors of light with the use of three LEDs, i.e., a red LED, a blue LED, and a green LED and (ii) a method in which white light is generated by mixing blue light and yellow light by using a blue LED as a light source for a yellow fluorescent substance. Further, some techniques have been proposed to generate white light whose color can be adjusted and which is excellent in color rendering property and in reproducibility (for example, see Patent Literatures 1 through 4).
However, according to the conventional techniques, a degree of integration of a plurality of LED devices cannot be increased because of a restriction such as a size of packaged components, and accordingly a spatial mixed color performance is low. This causes a problem that the plurality of LED devices are more likely to emit respective bright spot lights, and therefore color unevenness easily occurs. The following description will discuss this problem with reference to FIG. 23.
FIG. 23 illustrates how colors are mixed in a case where an LED device 951 which emits light of a color A and an LED device 953 which emits light of a color B are both provided on a single substrate 955. In this case, when the light sources are directly viewed, the light sources are separately viewed as two light-emitting points of different colors. Further, a spatial mixed color performance of the light of color A and the light of color B is low. This causes the LED devices more likely to emit respective bright spot lights, and therefore color unevenness easily occurs (e.g., shadows of an object become different colors). Note that this problem occurs even in a case where the LED device 951 and the LED device 953 emit lights of identical colors.
In view of this, a technique has been proposed in which a spatial mixed color performance is improved by adjacently arranging the LED devices 951 and 953 (for example, see Patent Literature 5).